Britus International School - Metals (PDF)

Elements Classification: Metals What metal do you think most important in our daily life and why? Lesson objectives: Audience: Students in Grade 11 Chemistry Behavior: Given a periodic table, students will be able to identify metals based on the...

Elements Classification: Metals What metal do you think most important in our daily life and why? Lesson objectives: Audience: Students in Grade 11 Chemistry Behavior: Given a periodic table, students will be able to identify metals based on their location. Condition: Using a periodic table and a list of elements. Degree: Students will correctly identify at least 80% of metals in a given an activity. Success criteria: Emerging: Can identify common metals (e.g., gold, silver, copper) on the periodic table. Developing: Can describe the general location of metals on the periodic table. Meeting: Can correctly identify metals on the periodic table, given a list of elements. Exceeding: Can explain the trends in metallic properties across a period and down a group. Think about the following statements: 8 minutes Steel, brass and bronze A All the B are called All elements of metals so metals C the Periodic they should are Table are be on the magnetic metals Periodic Table Try and complete all 3 tasks if you can. 1)Task 1: Copy each statement and say if it’s true or false. 2)Task 2: Rewrite any statement you think is false to make it true. 3)Task 3: Explain why you think each statement is true or Discussion/answers: What did you think? A) False scientists classify the elements into metals, non-metals and metalloids. B) False: Steel, brass and bronze are NOT elements, they are made up of mixtures of metals- called ALLOYS. C) False: You probably know that iron is magnetic but aluminium (eg used in drinks cans) is not. In fact, only iron, cobalt and nickel are magnetic.  Watch this video about the properties of metals https://www.youtube.com/watch?v=4gpEAj-Veio Listen carefully as there will be some questions to follow! ☺  5 minutes QUICK TASK: using the symbols on the periodic table shown, can you name… (a) a metal in group 1 (b) two magnetic elements (c) the only liquid Just write the answers, no metal need to copy out the (d) an metal(s) that question! could form a positive Possible Answers! a) Li, Na, K b) Fe, Ni c)Hg d) Be, Mg, Ca  5 minutes Match the key term to its Malleable definition Shatters when bent or hit Brittle Can be drawn out into a wire without snapping Ductile Can be bent or hammered without shattering Sonorous Shiny Makes a ringing sound when Lustrous hit Answers! Malleable Shatters when bent or hit Brittle Can be drawn out into a wire without Ductile snapping Can be bent or Sonorous hammered without shattering Lustrous Shiny  10 minutes PROPERTY METALS Appearance Task: State at room temperature Copy and complete the table on Density properties of metals Strength Malleable or brittle Conduction of heat Conduction of electricity Magnetic material Sound when hit  PROPERTY METALS Appearance Shiny State at room temperature Solid (except mercury, which is a liquid) Density High (they feel heavy for their size) Strength Strong Malleable or brittle Malleable (bend without breaking) Conduction of heat Good Conduction of electricity Good Magnetic material Only iron, cobalt and nickel Sound when hit They make a ringing sound (they are sonorous)  10 minutes METALLIC BONDING draw the diagram to show the bonding in metals  In metals, the electrons leave the outer shell of each metal atom forming positive metal ions. These electrons are free to move over the surface of the atoms and are called delocalised electrons. A metallic bond is the electrostatic force of attraction between the metal ions and the delocalised electrons. Answer the following three 8 minutes questions: Use your knowledge of metallic bonding to explain these properties of metals. Write out the questions and your answer. Attempt all questions if you can! a) Why are metallic bonds strong? b) Why do metals have a high melting point? c) Why do metals conduct electricity? Answers! a) Metallic bonds are strong because there are STRONG attractions between the delocalised electrons and positive ions. b) Metals have high melting points because there are strong attractions between the delocalised electrons and positive ions. A LOT OF ENERGY is needed to break the strong bonds. c) Metals conduct electricity because delocalized electrons can move freely, allowing electric current to Reflection : Summarize key takeaways from the lesson and preview upcoming chemistry topics. Three stars one wish